Modern mobile devices often include components for determining the current location of the mobile device. The mobile devices can include global navigation satellite system (GNSS) receivers for receiving GNSS signals. The GNSS signals can be used to estimate the current location of the mobile device. Accurate location estimation based on GNSS signals can require signals from four or more satellites. Location estimates can be improved by providing additional non-GNSS location information to the GNSS location estimation process.